Can not set correct resolution for external monitor

Question

I am using ubuntu 15.04 on my Asus X550L Laptop. Following is my lspci

$ lspci
00:00.0 Host bridge: Intel Corporation Haswell-ULT DRAM Controller (rev 09)
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 09)
00:03.0 Audio device: Intel Corporation Haswell-ULT HD Audio Controller (rev 09)
00:04.0 Signal processing controller: Intel Corporation Device 0a03 (rev 09)
00:14.0 USB controller: Intel Corporation 8 Series USB xHCI HC (rev 04)
00:16.0 Communication controller: Intel Corporation 8 Series HECI #0 (rev 04)
00:1b.0 Audio device: Intel Corporation 8 Series HD Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 1 (rev e4)
00:1c.2 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 3 (rev e4)
00:1c.3 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 4 (rev e4)
00:1c.4 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 5 (rev e4)
00:1d.0 USB controller: Intel Corporation 8 Series USB EHCI #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation 8 Series LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation 8 Series SATA Controller 1 [AHCI mode] (rev 04)
00:1f.3 SMBus: Intel Corporation 8 Series SMBus Controller (rev 04)
00:1f.6 Signal processing controller: Intel Corporation 8 Series Thermal (rev 04)
02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Device 5287 (rev 01)
02:00.1 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 12)
03:00.0 Network controller: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter (rev 01)
04:00.0 3D controller: NVIDIA Corporation GF117M [GeForce 610M/710M/820M / GT 620M/625M/630M/720M] (rev a1)

I have two monitors.

1. Dell 24 inch monitor, with native resolution of 1920X1080, which I can connect to my laptop without any problem and works out of the box.
2. Acer X193HQ, which has native resolution of 1366X768, and causing me the problem.

I tried connecting this Acer monitor in Windows 7 without any problem and works at the native resolution 1366X768.

But when I try to connect it in ubuntu I only get options for 2 resolution 1. 1024X768 2. 800X600

I am not able to set the Acer monitor to native resolution but my Dell monitor works fine.

Following is my xrandr

$ xrandr
Screen 0: minimum 8 x 8, current 2390 x 768, maximum 32767 x 32767
eDP1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
   1366x768       60.0*+
   1360x768       59.8     60.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
DP1 connected 1024x768+1366+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768       60.0* 
   800x600        60.3     56.2  
HDMI1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

I am using Nouveau display driver. I tried changing it to NVIDIA binary dirver version 340.76, but then I get the black screen on login.

I also tried adding other resolutions for DP1 using following commands

xrandr --newmode "1366x768_60.00"  85.86  1366 1440 1584 1800  768 769 772 795  -HSync +Vsync
xrandr --addmode DP1 1366x768_60.00

These commands successfully added resolution option in display settings (only for a session though) but when I tried to set it, the monitor is again revert back to 1024X768.

Please suggest.

Answer 1

You need to make the xrandr commands run on startup.

Unfortunately, a lot of people have trouble making the commands permanent, so that they run on startup, but I'll show you how to do it the easy way:

• Create a bash script, xrandr.sh for example, and place your xrandr commands into it. It should look something like this

  #!/bin/bash
  xrandr --newmode "1920x1200_60.00"  193.16  1920 2048 2256 2592  1200 1201 1204 1242  -HSync +Vsync
  xrandr --addmode VGA1 1920x1200_60.00
  xrandr --output VGA1 --mode 1920x1200_60.00

• Make the script executable with chmod +x xrandr.sh

• Search for "Startup Applications" in the dash, run it, and add the script as a startup application.

The commands will now run every time you log into your account.